Bench Dog Tools ProMax Instructions Manual page 9

Adjusting the Subfences
The two MDF (medium density fiberboard)
subfences are designed to slide along the fence
approximately 2". This results in a router bit
opening from 0 to 4".
A. "Close" Setting
Many applications require adjusting the subfences
close to the router bit. (Fig. 18) This accomplishes
nearly the same benefits of a true "zero clearance"
setting (see B) without cutting the subfences.
Before the router is turned on, and after the
fence and router bit height are properly adjusted,
slide the subfences toward the bit to reduce the
gap. Confirm that the router bit can freely rotate
without touching the subfences!
B. "Zero Clearance" Setting
Cutting the subfences into the router bit profile
produces "zero clearance". Zero clearance
eliminates the gap between the fence and router
bit. (Fig. 19) This prevents the workpiece from
getting pulled into the fence just before the router
bit. Moreover, a zero clearance setting achieves a
cleaner cut because the subfence supports the
workpiece fibers. If a true zero clearance setting
is desired, follow these steps:
1. Adjust the bit height and fence position.
Note: The subfences must NOT contact the
router bit at this time.
2. Install the bit guard and secure.
3. Start router, and use dust collection. From the
back of the fence, slightly loosen the subfence
knobs and carefully slide the infeed subfence
into the spinning router bit. Hold onto the
subfence knobs.
4. After the subfence has reached the guide
bearing of the router bit, fully tighten the
knobs on the subfence.
Note: If the bit does not have a guide
bearing (i.e. vertical raised panel bits), slide
the subfence half-way into the bit, then tighten
the subfence knobs.
Caution: Never adjust or slide the subfences
from the front! Always work from the back
with both hands on the adjustment knobs.
Important Notes:
The outfeed subfence is rarely set to zero clearance,
because doing so has little performance benefit and
MDF subfence
Fig. 18 - "Close" Setting
MDF subfence
Fig. 19 - "Zero Clearance" Setting
can damage the subfence. A "close" setting is more
desirable for most applications. Setting the outfeed
subfence to zero requires great care because the
router bit can cause a portion of the subfence to
chip or break. If an outfeed zero clearance is
absolutely necessary, slide the outfeed subfence
very slowly into the bit to minimize the chipping
and tearing.
The subfences can be flipped when changing
profiles or bit heights. New, replacement subfences
are available when a new profile is to be created
or if the subfence cannot be trimmed to provide a
fresh edge.
MDF works very well as a subfence because it is
softer than most woods and is much less likely to
damage expensive router bits. MDF also retains
the shape of delicate profiles and thus allows proper
support for zero clearance settings. When adjusting
the fence, ensure that no part of the aluminum
fence body could contact the router bit.
MDF subfence
MDF subfence
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